“The UN, they don’t know what they’re doing,” a well-known New York City real estate developer, Donald Trump, once told the Sun while in his office atop a Manhattan skyscraper bearing his name. Soon after, in 2008, the United Nations launched an ambitious renovation project without the aid of America’s future president. On Tuesday, Mr. Trump used that experience to illustrate Turtle Bay’s failure to live up to potential. 

Back then, Mr. Trump warmly greeted this Sun reporter to his namesake skyscraper, widening the conversation far beyond the subject at hand. A gracious host, he boasted about his greatest success in non-private construction: After New York City failed to renovate Central Park’s ice skating landmark, the Wollman Rink, Mr. Trump made it operational in what he described as “half the time and half the cost” of the project’s proposed renovation. 

Mr. Trump was itching to take up the renovation of the UN’s aging, crumbling, asbestos-riddled landmark at Manhattan’s Turtle Bay district. The headquarters building was erected on a site of former slaughterhouses. The property was purchased in 1947 on an $8.5 million grant from John D. Rockefeller.

For decades, the UN brass cited their status as an extraterritorial entity to reject visits by New York City building inspectors. The Turtle Bay landmark fell far behind construction standards imposed on all city buildings, and posed dangers to UN employees. Then, Secretary-General Kofi Annan decided to renovate.

The future American president told the Sun he’d be willing to do it with no profit for himself. “Many years ago, a very successful real estate developer in New York, known as Donald J. Trump, bid on the renovation and rebuilding of this very United Nations complex,” he told the General Assembly on Tuesday.

UN officials told the Sun later that Mr. Trump in fact never tendered a formal bid on the project. Yet, he did make his offer public in press interviews, as well as in a congressional hearing.

“I remember so well, I said at the time that I would do it for $500 million,” he said. “Everything would be beautiful.” Mr. Trump promised the UN marble floors and “mahogany walls,” while he said other constructors were “going to give you plastic.” He added: “But they decided to go in another direction, which was much more expensive at the time, which actually produced a far inferior product.”

In the opening of his Tuesday speech, the president noted that the teleprompter malfunctioned and that upon entering the building, the first lady almost tripped as the escalators stopped working. Indeed, some of the UN’s custom-designed escalators are closed for repairs on an almost daily basis.

The escalators and other parts of the building are non-functional despite years of renovation that forced relocation of offices to nearby high-rises. Initially budgeted at $1.2 billion, the project lasted much longer than originally planned, finally ending in 2017, and its costs ballooned to $2.31 billion, according to the UN figures. Outsiders estimate a higher cost. 

“They had massive cost overruns and spent between $2 and $4 billion on the building, and did not even get the marble floors that I promised them,” Mr. Trump said.